It has been proposed that, when a bump of an electrical element such as a semiconductor chip is connected to an electrode of a circuit board by anisotropic conductive connection, an anisotropic conductive film, in which solder particles having a melting temperature of 180 to 185° C. are dispersed in an epoxy-based thermosetting adhesive having a curing temperature of 195 to 200° C., is disposed between the bump of the semiconductor chip and the electrode of the circuit board, and then the obtained product is heated and pressurized so that the solder particles are melted, thereby metallically bonding the bump of the semiconductor chip and the electrode of the circuit board (Patent Literature 1). In this case, preheating is performed at a temperature between 120 to 130° C. so that the epoxy-based thermosetting adhesive is cured to some extent so as to regulate a range in which the solder flows when melted, and then substantial heating is performed at a temperature between 200 to 210° C. so that the solder particles are melted.